feat: add job cleanup loop, Scheduler task definitions, and registrar

- job_cleanup_loop (src/jobs/job_manager.py): hourly in-process pass over
  JobManager.cleanup_expired_jobs, started at app startup and cancelled
  at shutdown; Redis job payloads auto-expire but set memberships do not.
- docs/scheduler-tasks.md: the four production Scheduler task payloads
  for the deploy checklist - nightly integrity check 04:30, weekly
  quality report Sunday 03:00 (day_of_week=6, 0=Monday), daily Paperless
  orphan-cleanup 05:00 hitting the existing
  /maintenance/cleanup/paperless?user=jpmschweitzer&dry_run=false
  endpoint, and disabling test_example_task - with exact HTTP bodies
  (explicit user=jpmschweitzer, Authorization: Bearer ${LIBRARY_API_KEY}
  placeholder).
- scripts/register_scheduler_tasks.py: reads SCHEDULER_URL from env,
  DRY-RUN BY DEFAULT (prints the exact payloads, provably contacts
  nothing), --execute gated and requiring LIBRARY_API_KEY to fill the
  placeholder. NOT executed - definitions delivered for the deploy
  checklist only.

9 new offline tests (loop passes/error-resilience/cancellation, payload
schedules, explicit production user, placeholder, dry-run default).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QbFZyDvYksazX6nYQYZ67L

docs/scheduler-tasks.md

@@ -0,0 +1,159 @@
+# Scheduler Task Definitions (Phase C deploy checklist)
+
+Production task payloads for the homelab's database-driven **Scheduler**
+service. These are **definitions only** — nothing in this repo registers
+them automatically. Register them as part of the deploy checklist, either
+via the Scheduler UI/API or with the helper script:
+
+```bash
+# Preview exactly what would be sent (default):
+SCHEDULER_URL=http://<scheduler-host>:8090 \
+    .venv/bin/python scripts/register_scheduler_tasks.py
+
+# Actually register/update the tasks (deploy checklist step):
+SCHEDULER_URL=http://<scheduler-host>:8090 \
+LIBRARY_API_KEY=<the library-desk API key> \
+    .venv/bin/python scripts/register_scheduler_tasks.py --execute
+```
+
+Conventions:
+
+- All tasks call the **production** library-desk container
+  (`http://library-desk:8089`) with the explicit production tenant
+  `user=jpmschweitzer` (there is no default tenant — Phase B).
+- `${LIBRARY_API_KEY}` is a placeholder for the library-desk API key
+  (`LIBRARY_API_KEY` in the container env). Never commit the real value.
+- Schedule fields use the Scheduler's convention: `-1` = every,
+  `day_of_week`: `0` = Monday … `6` = Sunday.
+
+---
+
+## 1. Nightly integrity check — 04:30 daily
+
+Read-only report: pages without vectors, orphaned vectors, unexpected
+Qdrant collections, Document nodes without wiki pages. Caches its result
+in Redis for the weekly quality report.
+
+```json
+{
+  "task_name": "library_integrity_check",
+  "service": "library-desk",
+  "executor": "rest_api_executor",
+  "priority": 60,
+  "description": "Nightly read-only integrity check for the library (vectors/graph/wiki/collections)",
+  "enabled": true,
+  "max_retries": 2,
+  "timeout_seconds": 900,
+  "minute": 30,
+  "hour": 4,
+  "day_of_month": -1,
+  "month": -1,
+  "day_of_week": -1,
+  "config": {
+    "method": "POST",
+    "url": "http://library-desk:8089/maintenance/integrity-check",
+    "headers": {
+      "Content-Type": "application/json",
+      "Authorization": "Bearer ${LIBRARY_API_KEY}"
+    },
+    "body": {
+      "user": "jpmschweitzer"
+    }
+  }
+}
+```
+
+## 2. Weekly quality report — Sunday 03:00
+
+Runs the duplicate scan, flags stale/metadata-poor pages, folds in the
+latest integrity results, and writes the dated report page to
+`users/jpmschweitzer/system/quality-reports/YYYY-MM-DD`.
+
+```json
+{
+  "task_name": "library_quality_report",
+  "service": "library-desk",
+  "executor": "rest_api_executor",
+  "priority": 60,
+  "description": "Weekly library quality report (dedup, stale pages, missing metadata, integrity) written to the wiki",
+  "enabled": true,
+  "max_retries": 2,
+  "timeout_seconds": 1800,
+  "minute": 0,
+  "hour": 3,
+  "day_of_month": -1,
+  "month": -1,
+  "day_of_week": 6,
+  "config": {
+    "method": "POST",
+    "url": "http://library-desk:8089/maintenance/quality-report",
+    "headers": {
+      "Content-Type": "application/json",
+      "Authorization": "Bearer ${LIBRARY_API_KEY}"
+    },
+    "body": {
+      "user": "jpmschweitzer",
+      "stale_days": 30,
+      "dedup_threshold": 0.9,
+      "write_page": true
+    }
+  }
+}
+```
+
+## 3. Daily Paperless orphan cleanup — 05:00
+
+Hits the **existing** cleanup endpoint (query parameters, empty body).
+`dry_run=false` deletes vectors/graph nodes for documents that were
+removed from Paperless-ngx.
+
+```json
+{
+  "task_name": "library_paperless_orphan_cleanup",
+  "service": "library-desk",
+  "executor": "rest_api_executor",
+  "priority": 60,
+  "description": "Daily cleanup of vectors/graph nodes for documents deleted from Paperless-ngx",
+  "enabled": true,
+  "max_retries": 2,
+  "timeout_seconds": 900,
+  "minute": 0,
+  "hour": 5,
+  "day_of_month": -1,
+  "month": -1,
+  "day_of_week": -1,
+  "config": {
+    "method": "POST",
+    "url": "http://library-desk:8089/maintenance/cleanup/paperless?user=jpmschweitzer&dry_run=false",
+    "headers": {
+      "Authorization": "Bearer ${LIBRARY_API_KEY}"
+    },
+    "body": {}
+  }
+}
+```
+
+## 4. Disable `test_example_task`
+
+Not a new task: the leftover example task must be **disabled** (not
+deleted, so its history is preserved).
+
+```
+PUT ${SCHEDULER_URL}/tasks/test_example_task
+Content-Type: application/json
+
+{"enabled": false}
+```
+
+---
+
+## Related (already registered / in-process)
+
+- `knowledge_consolidation` — every 30 minutes, POST
+  `/consolidate/knowledge` (already registered; after the Phase C
+  consolidation repair its runs log `searches_processed` and
+  `duration_ms`, and searches are no longer consumed while the LLM is
+  unavailable).
+- Redis job-set cleanup — runs **in-process** inside library-desk
+  (hourly `job_cleanup_loop` started at app startup); no Scheduler task
+  needed.